Cooling system for marine engines



sept. s, 1932.

Filed Jan. 30. 1928 J. W. ARNDT COOLING SISTEM F011 MARINE ENGINES 2A Sheets-Sheet l A TTORNEYS Sept. 6, 1932. J. w. ARNDT COOL'ING SYSTEM FOR MARINE ENGINES 2 Shets-Sheet 2 'Filed Jan. so, 1928 INVETOR.

M zd ALZA, Liu/Ml A TTORNEYS Patented Sept. 6, 1932 NUNITED STATES PATENT ol-Flci-zA JACK W. .ARNDT, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BYNMESNE ASSIGNMENTS, TO OUTBOARD MOTORS ,CORPORATIONQ OF DETROIT, MICHIGAN ,v A` CORPORATION OF MICHIGAN .COOLING SYSTEM ron MARINE ENGINES j c r This invention -relatesto improvements in cooling systems for marine engines and particularly to an improved means for circulatlined displacement of water'in the ree movev ment of the device therethrough.

It is a further object to provide a novel and improved type of water inlet desi ed to receive water for cooling purposes with a minimum displacement of water through which the device is movin A In all devices heretofore used for circulating 'cooling water through the jacket systems of outward motor engines there has been considerable displacement of' water in such av way as to add materially to the power required for propulsion. Pumps or other parts projecting from the otherwise stream-lined surface ofthe submersible portion of the motor have produced power-absorbing eddy currents and similar effects have resulted from poorly designed water inlets ports. By using radial passages in the propeller blades and carefully designed communicating passages for water inlet and outlet I have'succeeded in eliminating not only the moving parts incidental to pump operation, but also the eddy currents andawkward designs of previous structures in which the elimination ofpumps has been attempted.

It is another important purpose of thisinvention to avoid heating the lubricant in the propeller drive gear housing and to avoid possible leakage of water therein, while also preserving a solid or substantial propeller shaft, by supplying coolant to the propeller exhausting pump passages through the propeller hub outside of the projected periphery of the propeller shaft so that the design or operation of the shaft and its bearings is in no wise altered.

In the drawings: v Figure 1 is a vertical section through a device embodying this invention.

Figure 2 is a front elevation of the motorl plane desig- Likeparts are identified by the same reference characters throughouty the several views.

The outboard motory in which thisrinvention is embodied for illustrative purposes is of a well lmown type including a bracket 5 for attachment to the transom of boat 6. j The engine is pivoted for steering pu oses, being provided with a bearing sleeve projecting down from its crank case 8 concentrical- 1y with aligned'crank shaft 9 and drive shaft 10. The sleeve is jcfurnaled in bearing element 11 of the bracket. A latch 12 'releasably engages the crank case 8 with the bracket to restrain it against steering movement during starting. Counter-clockwise oscillation of the latch from the illustrated engagement with the notched bracket releases the motor for normal steering. .f

The cylinders 13 'are provided with the usual jackets 14 to which coolant is supplied through pipes 151 and withdrawn through-A pipes 16. The present invention relates to the shaft and gear housing assembly and the means for circulating coolant through the cooling system including the jackets and pipes above described.

`The submersible housing element comprises integrally a gear casing 20 anda shell 21 of stream-line contour in horizontal cross section which rises thereabove approximately tothe normal water line. The casing 20 is provided with bearings at 22 and 23for the propeller shaft 25 which is driven by gearing 26 from drive shaft extension 27. There is also a bearing at 28 for such extension.

l The stream-lined shell 21 comprises a part ofthe drive shaft housing. Itis divided by shaft.

a bearingpartition 30 into front and rear compartments 31 and 32. Within the bearin partition or drive shaft casing 30,"the drive shaft 10 is splined for convenience to extension 27. For the purposes of this disu cussion, vthe two shaft elements may be regarded as one.

The front chamber 31 has a water inlet port at 33 in the form of a vertically elongated slot centrally disposed at the apex of the converging walls of shell 21. A screen is con vemently and strongly made by casting transverse rods 34 which span the slot like port. A baille 34 guides the incoming stream upwardly to prevent eddy currents while permitting circulation so as to prevent accumulations of foreign matter.

The location of the inlet slot is such thatv its screen is more protected than it would be on the projecting cap 35 for bearing 23. It

is so shaped and located where forelgn matter will not llodge because nof the divided stream of water which'passes at either side. Yet the movement of the devices will produce a powerful pressure causing a stream to enter the narrow ort. f

The cham er 32 has an outlet port at 36 which -is annular and surrounds bearing 22V. The bearing bushing preferably projects along the propeller shaft so that its packing 37 will readily be accessible upon removing the propeller. The fact .that the discharge stream of coolant is kept outside of the gear casing and of the propeller 'shaft avoids the ossibility of heating lubricant or diluting 1t with water or weakening the propeller The propeller 40 -has a hub ski-rt. 41 rotatably, although not necessarily closely, fitted to the submersible housing about' the outlet port 36. The annular chamber 42 within the propeller hub communicates directly with the port 36 and also with radial passages 43 in each of the propeller blades 44 which issue from the iforward faces of the blades at 45. During the rotation of the propeller, the wa'- ter in passages 43 is centrifugally expelled to induce a rather powerful current through chambers 31 and 32 andthe cooling system to which they are connected as hereinaft'er described.

The submersible housing carries an integral cavitation late 46 intermediate top and bottom and a s eg 47 attached to a closure member 48 whereby the gearing is readily accessible for lubrication and inspection.

The. submersible housing. and parts associated therewith as aforesaid are dirigible unitarily with the engine, being connectedtherewith by an intermediate housing element 50. This element is tubular for bearing in the abutment block 51, .the adjustment of which along the segmental guide arms 52 of bracket 5 4determines the upright position of the motor. The upper end of the housing element comprises sleeve A7 already described and the element is securedl ..cover plate 55 conforming in contour with the housing shell 21 to the top of which itis Integrally cast into the housing element 50 are inlet and outlet water pipes 57 and A58 which register and communicate with inletand outlet chambers 31 and `32. Be-

tween these pipes is the drive shaft 10 which enters casing sleeve 30 through a' boss 59 which centers the housing elements.

At eir upper ends-the pipes 57 and 58 termin te in fittings from which branch pipes 15 and 16. lead to and'from the water jackets as already described. The construction of outlet pipe fitting 6() .will be obvious.

Inlet pipe terminates in an annular manifold 61 provided with a clean-out plug 62. The purposel of the manifold is to carry the inlet stream to the back of the motor wherethe Y-fitting 63 connects to pipes 15 leading to the bottoms ofthe jackets.

The description of the system and circu` lating means is now complete. Water en-4 ters port 33 under such pressure as results from movement ofthe device and from subatmospheric pressure :induced at the outlet by the centrifugal impeller incorporated in the propeller. chamber 31, tube 57, manifold 61, tting 63, pipes 15, and jackets 14 to return by pipes 16, fitting 60, ytube 58, chamber 32, port 36,

The water then traverses l chamber 42, and radial discharge passages 43 and ports 45 to the body of water whence itl came. l

It will be clear'that the construction described ofers numerous advantages and the objects briefly outlined above are fully satised.

I claim:

1. In a marine power plant having a cool` ing system, the combination with a propeller shaft, of a member providing a bearing therefor and a port adjacent said bearing communicating with said system, a propelv ler on said shaft abutting the ported portion of said member and provided with an apertured hub adapted in rotation to receive a liquid directly from said port, said propeller having a radial passage from saidport for the discharge of such liquid.

2. A marine power plant comprising the combination with an engine cooling systemv and an engine driven submersible propeller shaft,.of a member having a bearing supporting said shaft and provided with Ia port communicating with said system and opening adjacent said shaft, a propeller having an apertured hub`communicating outside of said bearing 'with said port and revoluble with reference thereto, and blades provided with radial discharge passages leading from said aperture. V

3. A marine power plant comprising the combination with' a Water cooled engine having a jacket and va propeller shaft, of a support for said shaft provided with a bearing and a passage communicating with said jacket and opening outside of the bearing, a propeller having radially passaged blades and a hub portion revoluble adjacent said support and chambered to afford -communication ,outside of said shaft between the passage of said support and the passages of said blades, and means providing an inlet passage from a normally submersible part of said power plant to said jacket.

et. The combination with the cooling system of the engine of a marine motor includr; ing a submersible gear housing provided wit inlet and outlet ports, of conduit means connecting said system with said ports, a propeller shaft projecting 'from said housing, and a propeller on said shaft having a hub portion provided with an aperture registerable with said outlet port for the operative reception of water directly therefrom. and a blade portion with an outwardly opening passa-ge communicating with said aperture whereby centrifugally' to expel water so received.

` 5. In a marine power plant the combination with an engine having a cooling system and a propeller shaft, of means for circulating water through saidA cooling system comprising. a propeller on saidshaft having a `radial delivery passage and a portedv hub, a conduit leading to said system, and a conduit leading from said system directly to said port wholly outside of said shaft and having a terminal portion with respect to which said hub port is revoluble and in operative communication.

6. In a marine power plant, the combination with an engine havinga cooling system` and an upright drive shaft, of a propeller shaft, gearing connecting said shafts, a submersible gear housing enclosing said gearing and providing a bearing for tsaid propeller shaft, and means for circulating through said system a portion of the waterabout said housing, said means including a propeller on said shaft having a radial impeller passage and means outside of said housing and said shaft providing a conduit for liquid between said passage and said system.

7 In a marine power plant, the combination with an engine having a cooling system with a normally submerged inlet, of a propeller shaft driven from said engine, a bearing member provided with a bearing and a packing gland about said shaft and an exhaust port outside of said bearing communieating with the outlet of said system, and a propeller on said shaft and provided with a chamber with a sln'rt rotatably abutting said membenand adapted to receive coolant from said exhaust port,said chamber having radially opening apertures for centrifugal expulsion of liquid therefrom wholly extraneously of said bearing.

8. In an outboard motor, the combination `with an engine having a cooling system, an'

said hub wholly outside of said gear housing and bearing.

9. In an outboard with an engine and a cooling system; of a drive shaft, y.propeller shaft and gearing; a housing for said gearing providedWith a bearing for said propeller shaft and withl a stream-lined housing element for the lower part of said drive shaft having inlet and outlet passages wholly outside of said gear-housing and inlet and outlet ports of which the latter is adjacent and outside of said bearing; a propeller onsaid shaft provided with radial discharge conduits adapted during propeller rotation to receive water from said outlet inlet and outlet communication with said cdbling system and leading therefrom to motor, the combination port; and a drive shaft housing supporting at the apex, and the latter having an outlet port 'at the rear of the outside of said gear housing; a cooling system connected between said chambers; and means for lcirculating coolant through said chambers and system, said means comprising a propeller having a centrifugal delivery passage and a hollow hub fitted about said outlet port and adapted to withdraw liquid therefrom.

11. In a device of the character described, the combination with an engine Vhaving a cooling system, of a shaft housing means comprising an upper sect-ion provided with conduits and a lower section secured thereto and provided with ported forward and rearward inlet and outlet chambers and an intermediatedrive shaft bearing partition; and a gear housing connected with said lower section and wholly closed from vsaid chambers; together with a propeller shaft projecting from said gear housing adjacent the port of said outlet chamber and a propeller i anda collecting port registering with said outlet port and adapted to `draw liquid therefrom. v

12. As a new 'article of manufacture for encasingoutboard motor shafting and gearing, a' stream-lined submersible housing prov Aviding a coolant'passage having an inlet port in the form of a vertically elongated slot centered at the" forward apex of the housing intermediate the tp and bottom thereof.

13. As a new article of manufacture for encasing outboard motor shafting and gearing, a submersible housing providing a closed gear case at its lower end, a shaft case extending thereabove, Water inlet and outlet passages at before and behind said shaft case, a bearing at the rear of said gear case, and an annular port o 14. An outboard motor including the combination -with an engine having a cooling jacket and a drive shaft, of a housing element comprising al gear casing and having inlet and outlet water passages and an intermediate drive shaft case extending thereabove, and a. second housing elementn connecting said firstelement with said engine and provided with water passages communieating with said jacket and with an intermediate drive shaft case all registering with the corresponding parts of said first mentionedelement, together with a propeller shaft projecting rearwardly from said gear casing and operatively connected vwith said drive shaft, said outlet passage bein ported adjacent said propeller shaftfan a propeller having a skirt rotatably fitted to said firstv element -about said shaft and port vand blades provided with passages opening radially from within said skirt.

15. The combination in'an outboard motor, of a submersible unit having a. propeller shaft gear housing portion and a drive shaft housing portion, said latter portion having forwardly converging wall surfaces and an interior water supply passage opening through the forward apex of said wall surfaces wholly above said first mentioned portion.

16. Inan outboard motor, a submersible unlt having stream lined exterior surfaces -converging forwardly and including a wa- Vter passage having an inlet disposed at the forward apex of ,said surfacesywithin the zone of pressure created in the` movement of 'sald un1t, theapexbf sald surfaces be-l ing linear 1n lan upright directlon and said inlet being transversely narrow and vertically elongated whereby pressures thereon ywill be approximately uniform throughout the area of said inlet.

JACK W. ARNDT. y.

pening from said y outlet passage about said bearing.

D l S C L. A l M E R 1,875,912.-Jaclc W. Arndt, Milwaukee, Wis. COOLING SYSTEM FOR MARINE EN- 32. Disclaimer filed April 11, 1942,

GINES. Patent dated September 6, 19 by the assignee, Outboard, Marine and Manufacturing Company.A

Hereby disclaims claim 16 of said patent.

[Oicial Gazette May 5, 1942.] 

